From 3d1318a70a4b1439f980edb23cb7ecbe41f4c9f3 Mon Sep 17 00:00:00 2001
From: Carles Fernandez <carles.fernandez@gmail.com>
Date: Wed, 10 Oct 2018 00:17:42 +0200
Subject: [PATCH] Improve PVT accuracy for GPS L1

---
 src/algorithms/libs/rtklib/rtklib_pntpos.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/algorithms/libs/rtklib/rtklib_pntpos.cc b/src/algorithms/libs/rtklib/rtklib_pntpos.cc
index d4a10fe65..13a94502a 100644
--- a/src/algorithms/libs/rtklib/rtklib_pntpos.cc
+++ b/src/algorithms/libs/rtklib/rtklib_pntpos.cc
@@ -246,7 +246,7 @@ double prange(const obsd_t *obs, const nav_t *nav, const double *azel,
             else if (obs->code[i] != CODE_NONE and obs->code[j] == CODE_NONE)
                 {
                     P1 += P1_C1; /* C1->P1 */
-                    PC = P1 + P1_P2;
+                    PC = P1 - P1_P2;
                 }
             else if (obs->code[i] == CODE_NONE and obs->code[j] != CODE_NONE)
                 {